Just got this call too. You can listen to the message at http://archshrk.com/google-voice-for-tracking-spam but here's the message they left...
"...Work with their clients. To reduce balances on credit cards medical bills and unsecured debt with no fees. We are calling from the renegotiation department pertaining to your current bill reference number 589632. We are implementing this procedure under this directive and are calling to get your credit card reduced under Civil Code 17 88.14. If you are not interested in reducing your balances press 3. It is important that we do everything possible to lower your balances, and cut your debt in half. Press. 5 Now to be transferred to the renegotiation department press 5, to cut your balance is in half."
I received a call from this number. Caller ID said:IMPORTANT. When I picked up the phone The message began about the importance of cleaning the ducts in my home. I hung up after that.